Answer:
Angular momentum, 
Explanation:
It is given that,
Radius of the axle, 
Tension acting on the top, T = 3.15 N
Time taken by the string to unwind, t = 0.32 s
We know that the rate of change of angular momentum is equal to the torque acting on the torque. The relation is given by :

Torque acting on the top is given by :

Here, F is the tension acting on it. Torque acting on the top is given by :





So, the angular momentum acquired by the top is
. Hence, this is the required solution.
The energy of the wave will decrease.
The energy of a wave is given as
E = h f
where E = energy of waver
h = plank's constant
f = frequency of the wave.
From the formula , we see that the energy of the wave is directly proportional to the frequency of the wave. hence as the frequency of the wave decrease, the energy of the wave will decrease.
Answer:
A. 40N
B. 5m/s
Explanation:
A.
Impulse is equal to the area under the curve of a force vs. time graph. In this case, the area is in the shape of a triangle with base 8 (12-4=8) and perpendicular height 10:
<em>Area of a triangle = (1/2)bh</em>
A=(1/2)*8*10
=40
ANSWER: 40N
B.
<em>Impulse = mass * velocity</em>
40 = 8v
v = 5
ANSWER: 5m/s